如何用parsec解析uniprot文件？

本文介绍了如何用parsec解析uniprot文件？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我是Haskell的新手，但它似乎是我想学习的一门强大的语言。我正在采用parsec上真实世界Haskell的一章中的一些代码。我试图让我自己的版本解析uniprot文件的内容。这是一个由记录组成的文件（以>开头），每个记录由行组成。我的代码看起来非常接近于示例中的内容，但是我收到了很多错误 - 主要是类型。我的例外是除了其他我读取的文件（IO字符串）的输出，而不是一个字符串。如果有人能帮我理解我的方法有什么问题，我将不胜感激...... import Text.ParserCombinators.Parsec main :: IO（） parseSprot :: IO String - >或者ParseError [[String]] parseSprot input = parse uniprotFile（unknown）input where uniprotFile = endBy record eol record = sepBy lines（char '>'） lines = many（noneOf，\ n） eol = char'\\\' main = do parseSprot $ readFileuniprot_sprot.fasta putStrLnhey 解决方案 code> parseSprot 在签名中不需要 IO 。 parseSprot :: String - > ParseError [[String]] ... readFile 是一个 IO字符串。您可以通过将 readFile 动作的结果绑定到新的字符串 IO 操作。在 do 表示法中，可以将结果绑定到一个变量，其中< - main = do fileContents< - readFileuniprot_sprot.fasta $ b $ parseSprot 函数不会返回 IO 中的结果，您可以在任何地方使用。在 do notation中，我们通过使用不同的语法告诉绑定到变量的结果和声明之间的区别。 x 将结果绑定到变量。 let x = ... 声明 x 无论在右侧。 main = do fileContents< - readFileuniprot_sprot.fasta let parsedContents = parseSprot fileContents 要测试解析器在做什么，您可能需要 print the从 parse 中返回的值。 main = do fileContents < - readFileuniprot_sprot.fasta let parsedContents = parseSprot fileContents print parsedContents 如果没有 do 表示法，您可以将其写为 main = readFileuniprot_sprot.fasta>> =打印。 parseSprot >> = 第一次计算的结果并将其输入函数以决定接下来要做什么。 I am a newbie to Haskell, but it seems like a powerful language that I want to learn. I was adopting some code from the chapter in real world Haskell on parsec. I tried to make my own version of it parsing the content of a uniprot-file. This is a file that consists of records (that starts with ">"), and where each record consists of lines. My code seems very close to what is done in the example, but I am getting a lot of errors - mostly on types. My exception is among other that I am taking the output of readFile (IO string) instead of a string. I would appreciate it if someone could help me understand what is wrong in my approach... import Text.ParserCombinators.Parsecmain:: IO()parseSprot :: IO String -> Either ParseError [[String]]parseSprot input = parse uniprotFile "(unknown)" input where uniprotFile = endBy record eol record = sepBy lines (char '>') lines = many (noneOf ",\n") eol = char '\n'main = do parseSprot $ readFile "uniprot_sprot.fasta" putStrLn "hey" 解决方案 parseSprot doesn't need an IO in its signature.parseSprot :: String -> Either ParseError [[String]]...The result of readFile is an IO String. You can do something with this String by binding the result of the readFile action into a new IO action. In do notation you can bind the result to a variable with <-main = do fileContents <- readFile "uniprot_sprot.fasta"The parseSprot function doesn't return a result in IO, you can use it anywhere. In do notation we tell the difference between a result bound to a variable and a declaration by using different syntax. x <- ... binds a result to a variable. let x = ... declares x to be whatever is on the right hand side.main = do fileContents <- readFile "uniprot_sprot.fasta" let parsedContents = parseSprot fileContentsTo test what your parser is doing, you might want to print the value returned from parse.main = do fileContents <- readFile "uniprot_sprot.fasta" let parsedContents = parseSprot fileContents print parsedContentsWithout do notation you can write this as main = readFile "uniprot_sprot.fasta" >>= print . parseSprot>>= takes the result of the first computation and feeds it into a function to decide what to do next. 这篇关于如何用parsec解析uniprot文件？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！